mrpopo573

UPDATE: PROBLEM RESOLVED, found wiring short in aftermarket alarm that had been installed and then removed poorly by the previous owner.


So I'm at my wits and wallets end. My 2000 Maxima still refuses to idle when warm (after you leave the house, 5-7 minutes into the drive, first stop light, she dies)

Idle relearns fix this for random intervals of time, sometimes 50 miles, sometimes 150 miles, sometimes 5 miles.

If I can't trace this down I'm going to have to dump it at the auction.

WHAT I'VE REPLACED OR TESTED:
IACV
MAF
ECU (twice, the second time to confirm that the rebuild wasn't faulty)
TPS

The motor has no vacuum leaks, no harness breakage that can be found anywhere. Perfect spark plugs, fuel system, etc. Air filter perfect. Throttle body is clean. Car has no codes.

Power and Gas Mileage are perfect.

I luckily have a great shop that works for very cheap for our dealership, and I have used only Nissan OEM parts. I've had two mechanics put nearly 10 hours a piece into diagnosis. But regardless I've thrown nearly 1000 dollars at this problem, if not more.

It's depressing. Any ideas? Thanks guys, the forum has been a great resource.

CobraKing

mrpopo573, you're scaring me bro!

I picked up a 2000 Maxima GLE Auto for my wife about a month and a half ago (new driver) and on Monday it died out while she was driving back from work with P0505. Prior to the stalling on the Monday, car drove well but I'm still kicking myself for not scanning the car before buying it as the P0505 doesn't set off the SES/CEL light.

Local mechanic cleaned the throttle body, seafoamed the valves (probably unnecessary) and adjusted the throttle cables so that idle holds at 750-1000 RPM.

I'm a little wary of the throttle cable adjustment as it seems like a temporary fix but again the car drove well when I took it for a round on Tuesday night. New IACV and MAF (scored both for a good price) are on the way and I intend on disconnecting the electronic engine mounts (automatic tranny) when I get home today.

I know you mentioned that you've replaced the ECU twice, have you looked at the boards for any damage to them?

mrpopo573

board are damage free.

Flanker84

Did you check your coil plugs?

I just pass for that problem and the trouble was the IACV, a good deep clean and the idle keeps in the 1000-750 RPMs range. But I got the tiny little bit problem with one ignition plug that become faulty sometimes and the idle drops to 200-300 RPMs and to solve this I need to turn off the engine, wait 5 seconds and start it again.

mrpopo573

Coil plugs are perfect, I did replace a few of them a couple months back, with a corresponding code that went away. (misfire). The idle problem existed before and after this. The idle problem was there the day I got my car (after I purchased it at auction, through my families dealership)

VQ'rInWLA

iTrader: (83)

Have you fiddled with TPS, IACV, and throttle stop screw? What does it idle at normally?

QT1 5MT AE

iTrader: (6)

swap pcv valve for new oem, migght make it idle slightly better.

mista0406

iTrader: (22)

+1 ^^^^^ agreed

mrpopo573

UPDATE: Problem fixed.

Culprit? Aftermarket alarm, installed by a previous owner, cheap standard model that was "disabled" poorly, and after full removal from all connections to the ignition and factory alarm harnesses, car idles and functions perfectly. Just completed a 200 mile "idle intensive" stop and go road trip to test it. So a wiring short was the problem, but just not in the usual place near the strut tower....

So happy to have my car back, couldn't think of a car I have enjoyed more than this one.

VQ'rInWLA

iTrader: (83)

hmm definitely enlightened by that one.

mrpopo573

it was hard to spend nearly a month throwing hours of my time, others time ($$$), nissan oem parts at a problem that persisted. I spend one last ditch effort searching for shorts, in my driveway, and find the one thing I overlooked. A 100 dollar ebay alarm.

VQ'rInWLA

iTrader: (83)

an eGay alarm? wow...which one? *I was actually looking at getting one from there....

mrpopo573

haha. no idea, but consider it a viper copy, basic model with shock detection. The issue was that the wiring had blown an inline fuse, and was hooked into my harness in several key areas (for security, and then later when it was disabled by someone, it created a short causing my idle hell)

Unique thing I found, is that it was also the reason my rear side markers blinked with the turn signals. Pulled the alarm, and they stopped doing this.

VQ'rInWLA

iTrader: (83)

now I know not to cheap out on it....but im glad you took care of the problem. damn after throwing so much at it....an expensive process of elimination..

mrpopo573

Thanks, couldn't have breathed easier than I did today. Such a weight off my shoulders. A lot of mechanical pride swallowed when I couldn't trace this thing down. Plus side is that the car has a lot of new parts on it that I won't have to worry about.

I had a lot of doubts about my car recently, but now I know it wasn't anything to do with Nissan.

I would definitely spend good money if you get an alarm, and spend equally as much as it takes to have it installed well. The one I removed felt like a VHS cassette, it was crap.

VQ'rInWLA

iTrader: (83)

A lot of mechanical pride swallowed when I couldn't trace this thing down

Can definitely relate to that. Heck the alarm wouldve been the last place I looked as well!

mrpopo573

Irony is that I knew it was there the day I bought the car, and was more worried that removing it would cause problems. Laughable.

VQ'rInWLA

iTrader: (83)

How long have you had her?

mrpopo573

6 months

VQ'rInWLA

iTrader: (83)

And this issue wasnt present when you first test drove it?

mrpopo573

Bought at a dealer only auto auction (family car business.) Auction guaranteed, meaning I had it frame checked, compression, clutch, etc. Car did not act up until a few weeks later, and then the problem was always intermittent, sometimes didn't rear its head for a 1000 miles.

VQ'rInWLA

iTrader: (83)

No kiddding? What are you replace that alarm with now? Or maye reverting to factory anti theft?

mrpopo573

The factory alarm was the only alarm functional since I bought it. Someone, sometime before I got the car, installed and then later "uninstalled" an after market and left it mostly connected.

I don't live in an area where I need more than the factory keyless and alarm, as simplistic as it is.

VQ'rInWLA

iTrader: (83)

Youre good then. Have a factory key fob for it? If not my boy has a few hes selling.

mrpopo573

Thanks, I have 3 fobs actually, need to program the other 2 for the car, but I've stolen a few from Maximas that were traded in at our lot that had an extra.

VQ'rInWLA

iTrader: (83)

Ahh now to fulfill the cats curiousity....what are the plans for her now that you can actually focus on goals?

mrpopo573

lols. To drive the damn thing and not cringe every time I come to a stop light expecting it to die. I have PTSD from it.

Some tint is needed, and I have a JWT Popcharger going in tomorrow. Already have a catback. After that maybe a little stance.

VQ'rInWLA

iTrader: (83)

They have a pill for that. Just make sure it isnt a little blue one

How dark are you gonna go with the tint? What are you looking at for stance? Strut/spring? Coils?

mrpopo573

Haven't decided how dark. Washington State Patrol has made some comments about my tint before, but I just feign light sensitivity and they back off. That encounter had more to do with my radar detector than my tint. Stance is a hard one. My stock struts, I think are new replacements, because the ride is perfect and my car has 136k miles on it. However, my driveway has a wicked dip off the main street that I can barely clear now.

I forgot to mention that my next performance mod will be to have my exhaust guy build a better y pipe. He already has the mock up ready, just need to save up some more money for it.

VQ'rInWLA

iTrader: (83)

Youre running a custom y right now? Whats the ID on em? Unequal length I take it?

mrpopo573

No custom y pipe yet. Had my exhaust guy take some photos/measurements to make an improved one, much like the warpspeed y pipe, only a little cheaper and installed.

VQ'rInWLA

iTrader: (83)

going with 2.5"? Does he have a mandrel bender? Or crush?

Dmoney305

How much do the fobs go for ? I may need one

VQ'rInWLA

iTrader: (83)

Ill ask him and get back to you.

CobraKing

mrpopo573, glad to hear that your car's fixed!

My wife's car is throwing a P0505 (IACV) and a P0140 (02 sensor) but it also has an aftermarket remote car starter. Do you think the remote starter could be causing the stall symptoms?

mrpopo573

Thank you! Always do the IACV first, as that P0505 is not a joke. If you have electric motor mounts (if its an auto you do) unplug them. If the IACV shorts, the ECU can be ruined, however, a rebuild of your ECU is 199.00 dollars and the turnaround time is mere hours once he receives it.

Start with the IACV. Have the idle learn procedure done after you replace it and go from there. My alarm was a unique wiring issue, and only resulted due to the stupidity of a previous owner.

CobraKing

Thanks for the help brother!

Car's a 2000 GLE automatic, and I disconnected the mounts the day before yesterday. The problem here is that I purchased the car from a private dealer and I have no service records at all. Funny thing is that when I put they key on the ON position the SES light displays, however there's no active light when driving. I had to run an OBD II scan to pull the codes. I'm only hoping that dealer hasn't done any shady stuff to disable the SES light and sold the car with the P0505 and P0140...

When the car first stalled I took it to a local mechanic and he cleaned the throttle body but he had to manually adjust the throttle cables to keep the idle at 1000 RPM. I do not believe that this is the right fix though... Additionally does the manual adjustment create any slack in the accelerator pedal?

In the interim I have an IACV and MAF on order. Would disconnecting the negative terminal suffice or is an Idle ECM relearn mandatory for our 2000 models?

mrpopo573

If the SES light displays during pre start, its functional. I don't know of a way to disable the SES light other than removing the actual bulb from the cluster.

The local mechanic didn't do you any help, cleaning the throttle body is great, but manual adjustment to the cables is not something I've seen nor would want done to my car.

Get the IACV put in. Do the idle re learn procedure, follow the instructions carefully. Its a mandatory thing. Unplugging the battery does nothing to teach the car idle specs.

Perhaps find a mechanic a little more Nissan competent. The New MAF is not a bad thing, but could be a waste of money. MAF problems are usually felt as a wall in the rpm band, like a limit on the throttle (power issue).

If the IACV does NOT fix the issue, inspect the computer for damage by pulling it and removing the cover. The MOSFET power arrays usually show burn damage from the short. These guys will take care of you: http://stores.ebay.com/MODULE-REPAIR-PRO

CobraKing

Looks like you and I are burning the midnight oil eh! Thanks a ton for the suggestions - I'll follow them and re-advise.

With regards to the manual cable adjustment - the car does indeed run, but when my foot's off the gas it won't slow down. Instead it continues to maintain speed. I surmise that this is in part to the idle being manually adjusted.

Either way thanks again, I'll be making these repairs as soon as I receive the parts!

mrpopo573

Its only 11pm here in Washington : )

Have the manual cable thing undone after the IACV fix. Let me know! Best of luck!